Biology 58 (2008) 173–198 www.brill.nl/ab

Ontogenetic and sexual variation in the coloration of the lacertid Iberolacerta monticola and Podarcis bocagei. Do the females prefer the greener males?

Pedro Galán Departamento de Bioloxía Animal, Bioloxía Vexetal e Ecoloxía, Facultade de Ciencias, Universidade da Coruña, Campus da Zapateira s/n., 15071-A Coruña, Spain e-mail: [email protected]

Abstract Changes in the coloration of the lacertid lizards Iberolacerta monticola and Podarcis bocagei with age in populations from NW Spain are described. Th e onset of sexual maturity in P. bocagei males involves a change in the ventral (yellow) and dorsal (green) colorations, which is diff erent from immature males (dorsally brownish in color). In I. monticola males, the ventral coloration also changes to a deep green when they reach maturity, while the dorsal coloration remains brownish as in the immature specimens. In this , the green dorsal coloration is acquired gradually after maturity. Only the oldest individuals have a predominantly green dorsal coloration. Th e diff erences between the two species in the time males take to acquire the green dorsal coloration could be related to their diff erent longevity. Th e coloring is acquired gradually in the most long-lived species (I. monticola ). A fi eld study was carried out on the behav- iour of adult males of I. monticola during the reproductive period. Th e males with green dorsal coloration were seen to pair with females signifi cantly more frequently than those with the brownish dorsal color. Th e increase in the green dorsal coloration (conspicuous) with the size and age of the males of this species would appear to have a clear function as an intersexual or intrasexual signal.

Keywords Coloration; ; ontogenetic color changes; ; sexual dichromatism; sexual selection

Introduction Th e coloration of the body has a wide social signifi cance in vertebrates (Andersson, 1994; Espmark et al., 2000). Many species use body color as a form of communication, for example as a means of sexual recognition and a way to send out information on their capacity to fi ght or their sexual stage (Cooper and Greenberg, 1992; Houde, 1997; Cuadrado, 2000; LeBas and Marshall, 2000). In the case of reptiles, many species of , especially from the Scleroglossa clade (including some scincids, cordilids and lacertids), sexual recognition is often based on color signals, particularly in species that

© Koninklijke Brill NV, Leiden, 2008 DOI: 10.1163/157075608X328026 174 P. Galán / Animal Biology 58 (2008) 173–198 present marked sexual dichromatism, where the males usually display more conspicuous colors than the females (Vitt and Cooper, 1985; Cooper and Greenberg, 1992; Olsson, 1994). Th ese Scleroglossa lizards use visual displays in interactions, which are an indica- tion of aggressiveness or the intention to mate (Díaz, 1993; López et al., 2004; Pough et al., 2004). Th e intensity of the conspicuous coloration of the males of some species would seem to be important in terms of the aggressive interactions between individuals of this sex, providing us with information on their fi ghting capacity (Olsson, 1994). However, there is little evidence that these bright colorations in males are important to the females when choosing a partner (Olsson and Madsen, 1995; Tokarz, 1998). Th ere is also little evidence that the females of many lizard species make an active choice of a partner based on visual characters (Olsson and Madsen, 1995, 2001; LeBas and Marshall, 2001; Olsson, 2001). Th e marked sexual dichromatism of many lizard species, especially in those where the males develop a bright coloration during reproduction, might be related to signals regard- ing the sexual recognition of males who are searching for a partner. However, experi- ments carried out with the lacertid Podarcis hispanica show that chemical signals have preference over visual signals in sexual recognition (López and Martín, 2001). In spite of this, coloration can play an important role in communication in certain saurian species, co-existing along with chemical signals, at least in those exhibiting marked changes of both an ontogenetic and seasonal nature, in the pigmentation of one of the sexes (Galán, 2000). Both types of signals are important depending on the context. Th erefore, visual signals could be important for long-distance communication whereas chemical signals are useful at shorter distances (López and Martin, 2001; López et al., 2004). Two species of small-sized lacertid lizards live in the north-west corner of Spain (northern Galicia). Th ey are endemic to the north-western area of the Iberian penin- sula: Bocage’s wall lizard (Podarcis bocagei), which lives primarily on slopes and in areas of scrub, and the (Iberolacerta monticola ; previously Lacerta monti- cola), which lives in rocky and stony areas. Both species can live in the same areas and coexist in certain habitats, such as stone walls or clearings in woods (Galán and Fernández, 1993). Iberolacerta monticola is a species with a high variability in dorsal coloration and design, especially the adult males, whose dorsal color can vary from brown to bright green, with a complex pattern of black spots arranged irregularly over the coloration (Arribas, 1996; Martín, 2005). Th is dorsal coloration is particularly developed in males from low-altitude populations in Galicia (north-western Iberian peninsula), displaying a marked contrast between the brown, green and black colors, especially during the reproductive period (Galán and Fernández, 1993; Galán, unpublished). Podarcis bocagei is less variable in color and design. Th e adult males have a green dorsal band, whereas the fl anks are brown. Th e black pattern usually forms longitudi- nal lines and irregular spots (Galán, 1986; Galán and Fernández, 1993). In the two species the bright dorsal colorations (greens) of the adult males develop during the reproductive period, from April to July, becoming less intense or going back to brown the rest of the year (Galán and Fernández, 1993; Galán, 1995). P. Galán / Animal Biology 58 (2008) 173–198 175

Th ese two lizard species are considered “small-sized lacertids”, however, I. monticola is, on average, 16% larger than P. bocagei. Correlated with this, the diff erences in their life histories are important. I. monticola males reach sexual maturity on average a year later (2-3 years as opposed to 1-2 for P. bocagei; Galán, 1996, 1999a; Rúa and Galán, 2003) and the maximum longevity of I. monticola males (8 years of age) is twice as high as that of the P. bocagei males (4 years of age). Th ese two characteristics (age at maturity and lon- gevity) are closely related (Bauwens and Díaz-Uriarte, 1997). Th erefore, of the varying degrees in the life history patterns of lacertids, ranging from species having short life spans and early sexual maturity at one end, to species that are long-lived and attain sexual matu- rity later, at the other (Bauwens and Díaz-Uriarte, 1997), P. bocagei would come closer to the former, while I. monticola would be more similar to the latter (Galán, 1999a; Rúa and Galán, 2003). With regard to other life history pattern characteristics, such as multiple clutches in the same year (up to 2 in I. monticola and 3 in P. bocagei ) and clutch size (an average of 6 eggs in I. monticola and 4 in P. bocagei) (Galán, 1991, 1997, 1999a; Rúa and Galán, 2003), their positions are somewhat diff erent in this multivariant covariation axis of the life history patterns reported by Bauwens and Díaz-Uriarte (1997). Ontogenetic changes in color are very common in reptiles, but they continue to be a poorly understood phenomenon in many species (e.i., Hawlena et al., 2006; Germano and Williams, 2007). For this reason, the following aspects will be studied in this arti- cle: (1) Th e ontogenetic changes in the coloration of the diff erent parts of the body of Iberolacerta monticola and Podarcis bocagei , from birth to sexual maturity. (2) Changes in the dorsal coloration of the males of these two species after reaching sexual maturity. In the event they do occur, the extent to which such changes are related to the size and age of the individuals. (3) Finally, an attempt will be made to contrast the hypothesis that the change in dorsal coloration from brown to green in males is related to sexual recognition. Also if the green dorsal pigmentation in males is found to increase over the course of the adult life in either of the two species, this could be related to sexual recognition cues taken by the females. Hence, the study will focus on the behaviour adopted by the diff erently-colored adult males with respect to the females (courting and mate guarding) in the fi eld.

Material and methods Two populations of Iberolacerta monticola located in the fl uvial valleys of the rivers Eume (UTM: 29T NJ70) and Mandeo (UTM: 29T NH79), in the province of A Coruña, Galicia, north-western Spain, were studied. Th ese populations occur in the same geographical (Artabrian Gulf) and climatic (Wet Oceanic climate type) area, at a similar altitude (50-200 m above sea level, Galán, 1982) and type of habitat (rocky outcrops, slopes and walls in Atlantic Quercus robur forests with Alnus gluti- nosa, Betula alba and Castanea sativa mixed with reforestation of Pinus pinaster and Eucalyptus globulus). Th e annual and reproductive cycle of both populations is very similar (Galán, 1991; Rúa and Galán, 2003). Th ree populations of Podarcis bocagei have also been studied; two in the same locations as I. monticola (valleys of the rivers Eume and Mandeo), where they live in sympatry, and a third in Carral (UTM: 29T 176 P. Galán / Animal Biology 58 (2008) 173–198

NH58), situated at a distance of 12 and 24 km respectively from the others, in the same geographical and climatic area, at a similar altitude (90 m above sea level) and habitat. Th e annual and reproductive cycle of these three populations is also similar (Galán, 1997, 1999a). Th e aim of the study was to monitor, over a period of several years, individuals marked by a code which combines toe clipping with the arrangement of the cephalic plates and other scalation characteristics, able to be determined thanks to the high interindividual variability in scalation in these lacertid lizards species. Seven highly variable scalation characteristics were considered: contact pattern (separated plates, contact at one point, broad contact) between: (i) rostral-frontonasal, (ii) frontonasal- frontal and (iii) interparietal-occipital plates, (iv) presence and location of supernu- merary scales, the number of (v) maseteric and (vi) supratemporal plates on the left and right sides of the head, and (vii) number of perianal scales (and any other anomalies of the plates). Th is combination of toe clipping with these seven individual scalation characteristics allowed us to identify the individual when recaptured, including those marked as juveniles several years later (see below). A photograph of the dorsal pattern of the adult individuals accompanied the code. Th e marking and recapture period lasted from 1989 until 1996 in the Eume and Carral areas and from 1993 until 2004 in the Mandeo. Several gravid females (with oviductal eggs) of both species from these areas were taken to the laboratory where clutches were obtained and incubated until eclosion took place. Th e hatchlings were marked individually as described and set free in the place where their mothers had been captured, together with their mothers (I. monticola : Galán, 1991; Rúa and Galán, 2003; P. bocagei : Galán, 1997, 1999a). Th e recapture records of these juveniles over the following years enabled us to obtain information on their growth, age and size at which they reach sexual maturity, longevity and the changes that occur in their coloration, during both the subadult and adult phases. After monitoring the marked individuals of both species throughout the annual cycle (from February to October) it was observed that the dorsal coloration in adult males undergoes signifi cant seasonal variations, in the same way that the green dor- sal pigmentation shown by some individuals during the reproductive period (from April to June) becomes brown or grey-green the rest of the year (from August to March; Galán, 1995, unpublished). Th erefore, and for the purposes of this study, only the individuals captured during the reproductive period of both species, between the months of April and July (Galán, 1991, 1997, 1999a; Rúa and Galán, 2003), when this coloration is at its highest level of development (Galán, 1995 and unpublished data), were taken into consideration. Individuals were captured by noosing or by hand. Th e mark of each individual was recorded (in the case of recaptures, for identifi ca- tion), according to age class ( juveniles, during their fi rst calendar year; subadults, from the beginning of the second calendar year up until the onset of sexual maturity, and adults: I. monticola , males SVL>52 mm, females SVL>56 mm; P. bocagei , males SVL>50 mm, females SVL>45 mm), sex, snout-vent length (with a precision of 0.1 mm with a digital calliper), weight (with a precision of 0.1 g with a Pesola spring balance) and dorsal P. Galán / Animal Biology 58 (2008) 173–198 177

coloration (back and fl anks), ventral coloration (ventral and gular areas) and tail colora- tion. For tail coloration, with broken, injured or regenerated tails were not considered. In the case of the dorsal coloration (granular dorsal and fl ank scales), the number of dorsal scales of each color in a ring in the center of the body was also counted (see below). Th e coloration used as a reference was based on the standard color keys according to the Pantone code and the Color Atlas (Küppers, 1994), which has been used in the past to defi ne the coloration of other Lacertidae (Galán, 1995, 2000). Since the angle at which the light hits the scales aff ects color perception, coloration was determined in all cases under good lighting conditions (natural, outside light). Th e lizard was hand-held, perpendicular to the observer, who proceeded to compare the coloration of each area of the body with the standard color layers (Küppers, 1994). Th e most similar color code was recorded. Once the coloration of the diff erent parts of the body had been determined, the coloration of the dorsal scales in a ring in the center of the body was recorded using a hand-held 10x magnifying glass. All the observations were carried out by the same person. Diff erentiations were made between the following colors (color coordinates accord- ing to Küppers, 1994): (1) Green: color coordinates: N 00 and N10 and > C50 , >A 50 and from A 40 to A99 and >C50 , A50 , A 70 . Pale yellow : N00 and

A 50. (7) Blue or blue-green. Blue : N00 and >C 50 , C 50 ,

>A 50 . Th ese color categories were clearly diff erentiated, and colors were identifi ed within the central range of each category, to avoid any overlapping categories. Given the diffi culties entailed in comparing the color tones of the dorsal coloration (granular dorsal scales, which cover the animal’s back and fl anks) with a magnifying glass, only three colors were diff erentiated: (1) green, (2) brown and (3) black. Scales of each color were counted in a ring in the center of the body. Th is enabled us to quan- tify the expanse of each of the three colors. Th is method of quantifying dorsal colora- tion was used in all age categories, in both males and females, although in the latter, dorsal coloration generally remained brown throughout their lives. In the case of ventral coloration (including the gorge), four colors were distinguished: (1) green, (6) pale green, (5) yellow or pale yellow and (4) white or whitish. Finally, as regards tail coloration (dorsal area of the upper half) three categories were able to be distinguished: (1) green, (2) brown and (7) blue or blue-green. Since the colors were found to show a continuous variation between diff erent tones, well-defi ned color categories were chosen, thus enabling us to clearly assign a color to each scale. In the event of possible confusion (between blue and blue-green, for exam- ple), a single color category was chosen. It must also be taken into account that in addition to the colors discernible within the visible spectrum of the human eye, other species can detect the near UV, including some lizard species (Fleishman et al., 1993; Th orpe and Richard, 2001). Preliminary studies carried out on Iberolacerta monticola would indicate that certain areas of the 178 P. Galán / Animal Biology 58 (2008) 173–198 body whose coloration is already bright (for example, the blue axillary ocelli and blue or white dots on the lower lateral part) could also be UV-refl ecting and may be used in intraspecifi c communication (Arribas, 2002). All of these structures already present bright colorations in the visible spectrum, thus the UV refl ectance would make them even brighter to animals able to see this part of the spectrum (Arribas, 2002). In this study, however, only the colorations in the visible spectrum will be considered.

Ontogenetic variation of coloration For this part of the study, the coloration of individuals of all age classes was studied ( I. monticola, n = 376; P. bocagei , n = 362). Th e coloration of the diff erent parts of the body was also recorded: dorsal coloration (considering the back and fl anks separately, not counting, in this case, the number of scales of each color, and comparing the gen- eral color of each area using the Küppers system), ventral coloration (ventral area and gorge) and tail coloration. Here, only the green or brown colors and not the pattern of black marks found over the coloration of these individuals was considered (despite the fact that the expanse of this black pattern was sometimes greater than the green or brown background coloration). Although the variation in color and design is continu- ous, in this case, individuals were divided into diff erent dorsal coloration categories according to the presence and extent of the green and brown dorsal and fl ank pigmen- tations. In Podarcis bocagei, the color of the fl anks stays brown in all the individuals throughout their lifetime. Th erefore only two categories of dorsal coloration were dif- ferentiated: (a) individuals with brown fl anks and back (B – B), and (b) individuals with green back and brown fl anks (G – B). In Iberolacerta monticola four categories were able to be discerned:(a) brown back and fl anks (B – B), (b) brown back and brown and green fl anks (B – BG), (c) brown and green back and green fl anks (BG – G), and (d) green back and fl anks (G – G). Th ese four dorsal I. monticola coloration categories are not random. Rather, they corre- spond to a gradient of sizes and ages, (a) pertaining to the youngest and smallest adult males and (d) pertaining to the oldest and largest adult males, bearing in mind that the green dorsal pigmentation fi rst appears on the scales of the fl anks, later spreading to the dorsal scales (see Results).

Changes in the dorsal coloration of the adult males For this part of the study, only sexually mature adult specimens were considered. Th e sexual maturity of the males was estimated by the presence of well-developed hemipenes (a visible bulge at the base of the tail) and the relative size of the femoral pores. However, since the only way to prove for certain whether or not an individual is sexually mature is by examining its internal reproductive organs, in previous studies carried out on these populations, a number of specimens of both species were dissected to determine the degree of testicle and epididymis development in relation to their body size (I. monticola , Galán, 1991; P. bocagei, Galán, 1996). Th is shed light on the size (SVL) at which the males of each species reach sexual maturity (males, I. monticola, SVL > 53 mm; Galán, 1991; Rúa and Galán, 2003; P. bocagei, SVL > 46 mm; Galán, 1996) and allowed us to P. Galán / Animal Biology 58 (2008) 173–198 179 relate it to certain external characteristics, such as ventral coloration. In this way, it was possible to determine whether or not a given individual was mature. Quantitative data on the degree of development of each coloration were obtained by counting the number of green, brown and black dorsal scales in a ring in the center of the body (a methodology similar to the one used to obtain an estimation of the number of dorsal scales in studies on lacertid ; see, for example, Darevsky, 1967; Galán, 1986; Arribas, 1996). In these lacertid lizard species, body coloration is arranged in somewhat irregular longitudinal bands or strips, all along the body with the diff erent colors extending in equal proportions. Th at is why the number of the scales of each color in a central ring of the body is a good descriptor of the entire body coloration. A hand magnifi er with a magnifi cation of 10x was used. If a scale had more than one color (not altogether infrequent), the most prevalent color was considered. As the number of scales of each color may vary greatly, depending on the row studied (due to the irregular distribution of the markings of each color), the count was carried out on at least two rows of non-consecutive scales. A third ring was counted if the values obtained in the fi rst two were signifi cantly diff erent. Subsequently, the average number of scales of each color for each individual was calculated. In contrast to the green or black pigmentation, brown coloration is markedly varia- ble between the diff erent individuals or depending on the dorsal region considered, especially in Iberolacerta monticola . In this species very light brown or ochre colorations in the dorsal area and dark brown colorations on the fl anks are predominant. However, in this study, they were all grouped together in a single brown coloration category, clearly distinguishable from the black and green colorations. Th is study did not consider the blue markings exhibited by most of the I. monticola adults in the axillary region (axillary ocelli) and on the external ventral scales, as a func- tion of already-known individual recognition (López et al., 2004). In the corporal region where they are located (axillae and ventral scales), they did not infl uence the color counts carried out on the dorsal scales. In all the population and morphological studies, P. bocagei has never been found to show blue ocelli.

Preference of females for the greener males Th is part of the study was carried out only on the Iberolacerta monticola , as male Podarcis bocagei adults showed no dorsal coloration variation during their adult life (see Results). Th e aim was to estimate the preference of I. monticola females for adult males with a diff erent dorsal coloration pattern by means of fi eld observations. In the populations of Iberolacerta monticola studied, the adult males exhibited mate guarding behaviour after mating with the females (Rúa and Galán, 2003; Galán, unpublished data). On the basis of observations, after copulation the male remains with the female for a period ranging from minutes to hours. No diff erent-sex adult individuals were seen together unless they had mated. When a male approached a female and courtship was not accepted on her part, the female moved away and did not remain in the proximity of the male. Th erefore, as an approximation towards 180 P. Galán / Animal Biology 58 (2008) 173–198 quantifying mating success in the diff erent adult males of the populations studied, observations of males in close proximity to a female (< 10 cm, usually in contact) were used as an indication that these animals had mated and that the male in question had not been rejected by the female he remained beside (Olsson and Shine, 1998; Moreira and Birkhead, 2003; Todd, 2005). Th erefore, during the months of May and June, the most intense period of mating of I. monticola in the study area, the adult males observed to have mated with an adult female (exhibiting male mate guarding behaviour) were collected by noosing and data on their biometrical parameters and coloration, as indi- cated above, were recorded (number of green, black and brown dorsal scales in a ring in the center of the body and areas of the body in which these colorations were con- centrated in relation to four categories). As a comparative sample, several adult males observed to be on their own, with no females in the vicinity, were randomly collected by noosing from the same populations and over the same time period. Data identical to the males exhibiting mate guarding behaviour were recorded. Th e number of dorsal scales of each color as well as the corporal marks, which allow us to determine an individual’s age, can only be identifi ed in animals that were col- lected and then observed in the hand. Hence, I also counted individuals not able to be captured, but observed in the fi eld and classifi ed into one of the four categories in keeping with the degree of brown and green dorsal coloration (B-B, B-BG, BG-G and G-G), in addition to animals that were captured but not marked (age unknown). However, in these cases only the following information was recorded: dorsal coloration category and whether or not they had mated or were alone. Th ese observations took place in the Eume and Mandeo populations every year from 1989–2004.

Statistical analyses In the text and tables, mean values are cited ± standard errors (SE). When an analysis of variance and covariance was used, normality was confi rmed fi rst. Homogeneity among variances was tested with the Kruskal-Wallis test and normality was tested with the Kolmogorov-Smirnov test. Data on the variables tested did not diff er signifi cantly from a homogenous and normal distribution of independent data. Data analysis was carried out with SPSS 11.0 software. To test the increase of SVL with age, polinomial regression (x = age in years, y = SVL) was used. One-factor ANOVAs were used to compare diff erences in green, brown and black coloration (number of dorsal scales of each color in a ring in the center of the body) with the age (in years) of the adult males of both species. I also used ANCOVAs to test these diff erences in the number of green, brown and black scales with age in years using size (SVL) as a covariate. Regression analyses were used to test the increase in the number of green, brown and black dorsal scales with age (in years) and size (SVL) of males. To determine if the I. monticola males with green dorsal coloration showed court- ship behaviour to the same extent as those with brown dorsal coloration, the Chi-square test (χ 2 ) was used. Finally, the diff erence in frequencies of I. monticola males observed paired with females and alone in relation to four categories of dorsal coloration (B-B, B-BG, BG-G and G-G) was tested using contingency table analysis (G statistic). P. Galán / Animal Biology 58 (2008) 173–198 181

Results Growth, sexual maturity and longevity of the males On the basis of the data obtained from the recaptures of males belonging to the two species and marked in the year of their birth, the age of several specimens was ascer- tained and related to their body size (SVL).

Iberolacerta monticola SVL increases signifi cantly with age (polynomial regression, x = age in years, y = SVL; 2 r = 0.921; F 2, 141 = 810.7; P < 0.0001), especially during the fi rst 3 years of life. Th e increase in size diminishes and growth is practically zero after 6-7 years of age. In spite of this, a signifi cant overlapping of sizes (SVL) between diff erent ages was observed, leading us to the conclusion that, except in the fi rst years of life, size alone is not a suitable way to estimate age. For this reason, the variation in the dorsal coloration was analyzed sepa- rately, with both size (SVL) and age (in years) of the individuals. According to recapture data on the individuals marked as juveniles in the year of their birth, males were found to reach sexual maturity at two years of age (third calendar year, 41%, n = 27) or three years of age (fourth calendar year, the remaining 59%) in the sample under study (com- bined data from all the populations studied). According to the information gathered, maximum longevity of the males from these populations was 8 years of age. In other populations higher maximum longevity fi gures were obtained (12 years of age in the population from the Lambre River, A Coruña).

Podarcis bocagei 2 SVL also increases signifi cantly with age (polynomial regression, r = 0.869; F 2, 95 = 309.4; P < 0.0001) especially during the fi rst two years of life. Th e increase in size diminishes and growth is practically zero after three years of age. According to recap- ture data, males reached sexual maturity at one year of age (second calendar year, 33%, n = 43) or at two years of age (third calendar year, the remaining 67%). According to maximum longevity data, the males from these populations reached 4 years of age. In other populations higher maximum longevity fi gures were obtained (6 years of age in the population from the Tower of Hercules, A Coruña).

Diff erences in coloration between age and sex classes Iberolacerta monticola Th e dorsal coloration of immature individuals (juveniles and subadults) and adult females is brown, whereas in adult males it is variable, with diff erent degrees of brown and green pigmentation ( table 1 ). Ventral coloration varies in the immature individu- als and adult females, but in this case all the adult males have the same green ventral coloration (table 1). A high percentage of the adult females has a ventral coloration similar to that of adult males. In the case of males, the onset of sexual maturity involves a change in ventral coloration, but not in dorsal color, which remains brown, as in immature individuals, the year they reach maturity. Th e green pigmentation appears 182 P. Galán / Animal Biology 58 (2008) 173–198

Table 1. Percentages of juveniles, subadults, adult females and males assigned to the diff erent categories of dorsal (back and fl anks), ventral, and tail color in Iberolacerta monticola . Th e black pattern appearing on the brown, green or whitish coloration has been omitted.

Adult males Adult females Subadults Juveniles (N=108) (N=92) (N=72) (N=90) Dorsal color Back Flanks Green Green 21.2 0 0 0 Green and brown Green 27.4 0 0 0 Brown Green and brown 16.8 0 0 0 Brown Brown 34.5 100 100 100 Ventral color White or whitish 0 0 33.8 100 Pale yellow 0 0 24.6 0 Pale green 0 7.3 41.5 0 Green 100 92.7 0 0 Tail color Green and brown 34.5 0 0 0 Brown 65.5 100 83.1 0 Blue or blue-green 0 0 16.9 100

gradually, over the course of their lifetime. Th e coloration of the integer tail is relatively constant in adults, variable in sub-adults, and has a bright blue or blue-green color in juveniles, during their fi rst calendar year.

Podarcis bocagei Th e dorsal coloration of the immature individuals is also brown, but in this species the adult females are the ones that show varying degrees of brown and green pigmentation, whereas all of the adult males have a green dorsal coloration ( table 2 ). Th e ventral coloration is variable in immature individuals and adult females, but all the adult males have the same yellow ventral coloration. A high percentage of the adult females has a ventral coloration similar to that of adult males ( table 2 ). In males, the onset of sexual maturity involves a change in the dorsal coloration of all the individuals from brown to green. Th e coloration of the integer tail is relatively constant in adults, variable in subadults, and has a bright green color in juveniles.

Diff erences in coloration between adult males Iberolacerta monticola Th e dorsal coloration (back and fl anks) of adult males (age ≥2 years; SVL ≥ 54 mm) changed notably over the course of the individuals’ lifetime. Th e extension of the green dorsal coloration (number of green-colored scales in a ring in the center of the body) varied signifi cantly with age (in years) in the adult individuals (ANOVA, F5, 88 = 101.4, P. Galán / Animal Biology 58 (2008) 173–198 183

Table 2. Percentages of juveniles, subadults, adult females and males assigned to the diff erent categories of dorsal (back and fl anks), ventral, and tail color in Podarcis bocagei . Th e black pattern appearing on the brown, green or whitish coloration has been omitted. Adult males Adult females Subadults Juveniles (N=113) (N=109) (N=65) (N=89) Dorsal color Back Flanks Green Brown 100 20.7 0 0 Brown Brown 0 79.3 100 100 Ventral color White or whitish 0 0 30.6 92.2 Pale yellow 0 27.2 69.4 7.8 Yellow 100 72.8 0 0 Tail color Brown 100 100 80.6 0 Green and brown 0 0 15.3 0 Green 0 0 4.2 100

P < 0.0001). Th e number of green dorsal scales increased signifi cantly, with both age 2 2 (polynomial regression, r = 0.815; F 2, 88 = 189.3; P < 0.0001) and size (SVL, r = 0.831;

F2, 96 = 230.3; P < 0.0001) ( table 3 , fi gs. 1 and 2 ). Using size (SVL) as a covariate, the number of green scales increased signifi cantly with age in years (ANCOVA, F6, 81 = 8.49, P = 0.005). Th e green coloration appears fi rst on the fl anks, and then on the back, start- ing at a certain size (SVL > 65 mm) and age (4th-5th year). After fi ve years of age and SVL ≥ 70 mm, the green coloration extends over a larger area than the brown coloration and individuals with completely green backs can be seen. Th e number of brown-colored scales also varied signifi cantly throughout the life- time of the I. monticola adult males (ANOVA, F5, 88 = 42.73, P < 0.0001), but, con- trary to what occurs with the green coloration, the amount of brown dorsal coloration (number of brown-colored scales) decreased signifi cantly, with both age (r2 = 0.691; 2 F2, 83 = 93.79; P < 0.0001; fi g. 2) and size (SVL, r = 0.673; F2, 94 = 94.83; P < 0.0001; fi g. 1 ). Using size (SVL) as a covariate, the number of brown scales decreased signifi - cantly with age in years (ANCOVA, F6, 81 = 3.83, P = 0.04). After monitoring the marked individuals, the brown-colored scales were found to turn green with age. Th erefore green scales increase in number while the brown scales decrease as the animals grow older. Finally, the number of black dorsal scales did not vary signifi cantly with age in adult individuals (ANOVA, F5, 86 = 1.88, P = 0.11). Th e number of black dorsal scales undergoes a slight increase with age and SVL ( fi gs. 1 and 2 ), although the diff erence 2 in number is barely signifi cant (age in years – no. black scales: r = 0.09; F2, 86 = 4.52; 2 P = 0.02; SVL – no. black scales: r = 0.075; F2, 94 = 3.72; P = 0.03). ANCOVA, SVL as a covariate, F6, 81 = 2.39, P = 0.13. 184 P. Galán / Animal Biology 58 (2008) 173–198 e N the variation in the the variation Range No black scales No Average ± Average 1 SE rity (see methods), and SVL in males of mature individuals were considered). Th considered). individuals were mature Range No brown scales brown No Average ± Average 1 SE Range No green scales green No Average ± Average 1 SE Range SVL (mm) Average ± Average 1 SE in A Coruña. Indicated in each case are the mean ± 1 standard error, the variation range and sampling size (N). To calculate To (N). range and sampling size the variation error, the mean ± 1 standard in each case are in A Coruña. Indicated Sexual Sexual maturity . Age (years) 012 NO2 NO3 59% NO 29.0 ± 0.64 41% YES 51.0 ± 0.6 41.6 ± 1.45 24 – 34 YES 58.1 ± 0.9 46 – 556 28 – 56 YES 0 54 – 657 0 YES 0 62.8 ± 0.58 0 YES 67.9 ± 0.3 59 – 68 YES 70.9 ± 0.4 – 65 – 71 YES – 4.5 ± 1.0 73.6 ± 0.2 – 69 – 73 19.1 ± 1.0 – 74.6 ± 0.2 72 – 74 0 – 19 24.4 ± 1.1 11 – 28 74.7 ± 0.3 42.3 ± 1.1 74 – 75 26.4 ± 1.4 42.0 ± 0.8 34.5 ± 1.9 20 – 31 41.8 ± 0.8 19.1 ± 2.1 74 – 75 33 – 50 29.0 ± 2.1 40.3 ± 2.1 23 – 34 37 – 47 22 – 49 33 – 48 7.8 ± 2.2 31.6 ± 1.9 15.3 ± 0.9 4 – 42 22 – 37 24 – 48 16.2 ± 0.7 7.0 ± 2.2 15.1 ± 1.5 15.4 ± 0.7 25 – 36 0 – 28 17.9 ± 1.6 8 – 22 15.5 ± 1.8 5.9 ± 2.6 11 – 21 6 – 26 0 – 20 8 – 23 4.0 ± 1.8 20.4 ± 2.6 20 3 – 29 7 – 28 16 0 – 19 22 21.5 ± 3.3 33 4 – 31 0 – 9 25 11 19.9 ± 4.3 8 – 32 11 24.8 ± 3.4 6 – 34 8 16 – 31 7 5 Table Table 3 Iberolacerta monticola Iberolacerta Number of dorsal scales, green, brown and black in color, in a ring in the center of the body, at each year of age, sexual matu at each year in a ring the center of body, and black in color, brown of dorsal scales, green, Number dorsal coloration of males, only adult specimens were used, 2 years of age and older (in the 2-year-old age class, only the 11 of age and older (in the 2-year-old used, 2 years dorsal coloration of males, only adult specimens were colors dark chestnut, dark brown, light brown and light ochre were grouped together in the count of brown-colored scales. scales. together in the count of brown-colored grouped were and light ochre light brown brown, chestnut, dark colors dark P. Galán / Animal Biology 58 (2008) 173–198 185

Figure 1. Relationship between the number of green, brown and black dorsal scales counted in a ring in the center of the body and body size (snout-vent length) in males of Iberolacerta monticola from A Coruña. Th e arrow indicates the size (SVL) at the onset of sexual maturity. 186 P. Galán / Animal Biology 58 (2008) 173–198

Figure 2. Relationship between the number of green, brown and black scales counted in a ring in the center of the body and age in years of Iberolacerta monticola males from A Coruña. P. Galán / Animal Biology 58 (2008) 173–198 187

Podarcis bocagei Unlike the species described above, the amount of green dorsal coloration in adult males (age ≥1 year; SVL ≥50 mm) did not vary signifi cantly with age (ANOVA,

F 3, 49 = 1.54, P = 0.21). Th e young adults (1-2 years old), with a smaller body size (average SVL 53-57 mm) have a similar number of green dorsal scales as the older adults (3-4 years old), of a larger size (average SVL 60-62 mm). No increase was 2 2 observed with either age (r = 0.09; F 2, 49 = 2.35; P = 0.11) or size (SVL, r = 0.09;

F 2, 49 = 2.47; P = 0.10) (table 4, fi gs. 3 and 4 ). Using the size (SVL) as a covariate, the number of green scales did not vary signifi cantly with the age in years either

(ANCOVA, F3, 40 = 0.93, P = 0.34). Nor did the number of brown and black-colored dorsal scales vary throughout the lifetime of the adults. Number of brown scales: ANOVA, F3, 44 = 1.13, P = 0.35 (age: 2 2 r = 0.01; F 2, 44 = 0.18; P = 0.83; SVL: r = 0.03; F 2, 44 = 0.65; P = 0.52; ANCOVA,

SVL as a covariate, F3, 40 = 2.07, P = 0.16) ( fi gs. 3 and 4 ). Number of black scales:

ANOVA, F3, 44 = 0.73, P = 0.54 (ANCOVA, SVL as a covariate, F3, 40 = 0.54, P = 0.47) (fi gs. 3 and 4 ).

Preference of Iberolacerta monticola females: fi eld observations Th e percentages obtained for the males paired with a female in relation to the type of dorsal coloration are very similar in the individuals whose ages were known (table 5) and in specimens observed and not collected and/or of unknown age (table 6). Th ese frequencies do not diff er signifi cantly (χ 2 = 4.48; df = 2; P = 0.106). According to the data from both tables, frequencies of individuals observed paired with females diff er signifi cantly between the four categories of dorsal coloration (specimens of known age: G = 15.23; df = 3; P = 0.0016; table 5; specimens of unknown age: G = 18.28; df = 3; P = 0.0004; table 6 ). In both cases, post-hoc analyses show that the observed values of paired males were higher than the values expected in the greener ones (G-G and BG-G). Th e only males that were observed paired with females had a green dorsal coloration, while those with a brown dorsal coloration were never seen beside a female. Furthermore, males with a greater amount of green dorsal coloration (green back and fl anks, G-G) were observed paired with a female a signifi cantly higher number of times than those with a smaller amount of green dorsal coloration (tables 5 and 6 ); specimens of known age: G = 11.01; df = 2; P = 0.0089; specimens of unknown age: G = 11.13; df = 2; P = 0.005). All the males that carried out mating in the study area (N = 10) had a green dorsal coloration (type G-G, eight times, and BG-G, twice).

Discussion No comparisons between two such phylogenetically diff erent species such as Iberolacerta monticola and Podarcis bocagei can be established (Bauwens and Díaz-Uriarte, 1997; Arnold, 2004; Carranza et al., 2004). However, diff erences in the life history of these two species, (particularly, those related to adult life span and longevity) may help explain the diff erences observed in the changes in the dorsal coloration patterns of males. 188 P. Galán / Animal Biology 58 (2008) 173–198 Range N No black scales No Average ± Average 1 SE rity (see methods), and SVL in males Range No brown scales brown No Average ± Average 1 SE Range No green scales green No Average ± Average 1 SE Range SVL (mm) Average ± Average 1 SE in A Coruña. Indicated in each case are the mean ± 1 standard error, the variation range and sampling size (N). (N). range and sampling size the variation error, the mean ± 1 standard in each case are in A Coruña. Indicated Sexual Sexual maturity Podarcis bocagei Podarcis Age (years) 011 NO2 67.4% NO3 32.6% YES 43.6 ± 1.04 YES 27.4 ± 0.9 52.8 ± 0.3 34 – 52 YES 22 – 35 51 – 55 YES 0 15.7 ± 0.8 0 57.4 ± 0.3 10 – 20 60.3 ± 0.2 54 – 59 62.4 ± 0.7 – 21.7 ± 1.4 59 – 62 14.4 ± 0.7 – 61 – 64 14 – 32 16.6 ± 1.0 10 – 22 17.0 ± 2.6 14 – 20 22.1 ± 1.5 23.9 ± 1.1 38.1 ± 0.8 12 – 21 36.6 ± 1.0 19.8 ± 2.8 13 – 33 18 – 30 30 – 46 25.7 ± 3.4 30 – 44 14 – 28 21.5 ± 1.4 20.3 ± 0.7 14 19 – 30 20.6 ± 1.0 24.0 ± 2.8 15 – 32 15 – 30 17.7 ± 2.3 14 – 25 15 – 30 23 29 14 – 22 25 8 5 of Table Table 4. of age, sexual matu at each year in a ring the center of body, and black in color, brown of dorsal scales, green, Number P. Galán / Animal Biology 58 (2008) 173–198 189

Figure 3. Relationship between the number of green, brown and black scales counted in a ring in the center of the body and body size (snout-vent length) in males of Podarcis bocagei from A Coruña. Th e arrow indicates the size (SVL) at the onset of sexual maturity. 190 P. Galán / Animal Biology 58 (2008) 173–198

Figure 4. Relationship between the number of green, brown and black scales counted in a ring in the center of the body and age in years of Podarcis bocagei males from A Coruña. P. Galán / Animal Biology 58 (2008) 173–198 191

Table 5. Field observations of adult I. monticola males having varying expanses of green dorsal coloration paired with a female (carrying out “male mate guarding” behaviour) and alone. (a) Th e general coloration is indicated, not the pattern of black spots. (b) Th e number of green scales was counted in a transversal ring of dorsal scales in the center of the body.

Dorsal Flanks No of green No of No of males coloration coloration dorsal scales SVL average Age males paired with (a) (a) (b) ± 1 ES (mm) (years) alone a female % Paired Green Green 26 – 35 74.2 ± 0.2 6 – 8 12 8 40.0 Brown and Green Green 18 – 25 69.6 ± 0.3 4 – 5 19 7 28.0 Brown Brown and Green 7 – 17 64.7 ± 0.5 3 – 4 26 1 3.7 Brown Brown 0 58.6 ± 0.6 2 – 3 16 0 0 Total 73 16

Th e most constant body coloration in the adult males of both species, at least in terms of hue characteristics, is the ventral color. In the two cases, the onset of sexual maturity involves the development of a constant, bright ventral coloration during the reproductive period, which, in the populations studied, is green in I. monticola and yellow in P. bocagei . Th erefore, the ventral coloration of adult males is clearly related to maturity. In other lizard species, males were also observed to acquire a characteristic ventral coloration upon reaching maturity (Lemos-Espinal et al., 1996; Pinto et al., 2005), a phenomenon which has been related to the infl uence of androgenic sexual hormones (Rand, 1992; Abell, 1998). Nevertheless, some minor diff erences between individuals with regard to the intensity of the ventral coloration have been observed. Th ey may be related to diff erences in sexual hormone levels, as has been suggested for other species of lacertids (Bauwens and Castilla, 1998), and possibly induced by genetic diff erences between individuals (Th ompson et al., 1993) or by diff erent blood parasite loads and immune system levels. Table 6. Field observations of adult I. monticola males having varying expanses of green dorsal coloration paired with a female (carrying out “male mate guarding” behaviour) and alone. Observations of specimens with an unknown age (not marked) and/or observed without being captured. No of males No of males paired with a Dorsal coloration Flanks coloration alone female % Paired Green Green 14 11 44.0 Brown and Green Green 25 6 19.4 Brown Brown and Green 34 2 5.6 Brown Brown 24 0 0 Total 97 19 192 P. Galán / Animal Biology 58 (2008) 173–198

Dorsal coloration, however, shows a diff erent variation pattern depending on the species. In P. bocagei maturity brings about the same type of change as in ventral colora- tion, with the brown dorsal color typical of immature individuals changing to green, a color exhibited by all the adult individuals during the reproductive period. Th is green- colored covering (the number of green scales) does not change signifi cantly once the animals reach maturity (at 1-2 years of age) until the end of their life, which has a rela- tively short longevity (4 years of age). By contrast, in I. monticola males, dorsal colora- tion does not change when sexual maturity is reached; it continues to be brown, like in the immature individuals. In the males of this species, the green dorsal coloration is acquired gradually after maturity is reached, over a period of several years. Th e number of green dorsal scales increases signifi cantly with the size-age of the individuals, while the number of brown dorsal scales diminishes. Only the older (≥5-6 years of age) and larger (SVL ≥70 mm) individuals have a predominantly green dorsal coloration. Although in Lacertidae species having a marked sexual dichromatism, green dorsal colorations are traditionally associated with adult males during the reproductive period, and brown coloration with the females (e.g., Olsson, 1994), even in the species studied here (I. monticola , Moreira et al., 1999; P. bocagei , Galán, 1995), variations to this gen- eral pattern have been found in these populations. Th us, a percentage of P. bocagei females had a green dorsal coloration, similar to that of males during the reproductive period while, on the other hand, a percentage of I. monticola adult males had a brown dorsal coloration, similar to that of the immature individuals and the females. Th e presence of green dorsal colorations in some P. bocagei females has been dis- cussed elsewhere (Galán, 2000). In this study, which focuses on adult males, an inter- esting observation was the fact that in one of the species (P. bocagei ), the onset of maturity led to the development of a bright mating coloration in all the individuals, which did not change for the rest of their adult lives. In the other species (I. monticola ), however, this did not occur. Th e bright dorsal mating coloration of the males did not appear after maturity, rather there was a period of several years, during which the brown scales gradually turned green. In this species, only the larger and older males have a green dorsal coloration. Th ere is a third dorsal color (black), appearing in the dorsal scales along with the green and brown colors, which showed no signifi cant variation over the lifetime of the individuals of both species. It may, however, show changes in the amount of relative cover, especially in I. monticola , as well as marked diff erences in the number and arrangement of the black marks between the individuals of the two species. So it is possible that diff erent proportions of the blackish marking pattern over the colored (i.e. green) part of the male dorsum, may aff ect the perception of a female sighting the male in question. Other colors, such as the blue ocelli in the lateral areas of the body, generally found in the axilliary areas, and blue spots on the lateral ventral scales (both only present in I. monticola), have not been taken into account in this study, although signifi cant changes in either their number or the amount of relative cover throughout the life- time of the individuals were not observed (Galán, unpublished; see, however, López et al., 2004). P. Galán / Animal Biology 58 (2008) 173–198 193

It is important to note that the relationship observed between the increase in the green dorsal coloration in I. monticola and the size and age of the individuals may vary among populations. Th ere are isolated populations of the Iberian rock lizard in several low altitude locations in the north of Galicia (Galán, 1982, 1999b). In this study, two of these populations (Eume and Mandeo) were examined, although others are know to exist where the increase in the green coloration and the decrease in the brown coloring occur at a faster (males take on a green dorsal coloration at a smaller size and earlier age) or slower rate (some brown coloration still remains even in larger and older indi- viduals) (Galán, unpublished). Th e populations studied here would fall somewhere in the middle between these two extremes. Variations in life history between the diff erent populations which aff ect, for example, longevity and age at sexual maturity, as well as population density, mortality rates, etc., could be related to diff erences in the speed with which changes take place in the dorsal coloration of adult males (Sinervo et al., 2001; Taylor and Caraveo, 2003; Macedonia et al., 2004). Th e complex coloration patterns, as shown by the adult males of these two species, can generally be explained, in adaptive terms, as an interaction between the sexual selection of bright, conspicuous colorations and the natural selection of cryptic colora- tions (e.g., Stuart-Fox et al., 2004 and references included in this article). In this study the hypothesis was put forward that this balance between the need to be conspicuous as a sexual signal and the need to be cryptic in order to avoid predation, is fulfi lled by the dorsal coloration pattern of the adult males of these two lacertid species. Th e green coloration, which is either acquired abruptly after maturity in P. bocagei, or varies throughout the lifetime of the individual, increasing with age and size in I. monticola , would have a conspicuous role, as a sexual signal. On the other hand, the black dorsal coloration, in the form of irregular or reticulated markings, would have a cryptic func- tion, and therefore its relative cover did not vary signifi cantly throughout the lifetime of these animals. Assuming a cryptic function of the black (and brown) dorsal pattern, related to camoufl age and the survival of the individual, and a conspicuous function of the green dorsal coloration, related to intraspecifi c recognition cues, why in one of the two spe- cies (P. bocagei ) is the green dorsal coloration of the males acquired abruptly with the onset of sexual maturity, while in the other (I. monticola ) it is acquired progressively over the years, after maturity? Th is may be explained by diff erences in longevity between the two species. Podarcis bocagei males belonging to the populations studied live for a maximum of 4 years, and have only 2-3 years of adult life. On the contrary, I. monticola males can live for up to 8 years, 5-6 of which are adulthood. In P. bocagei there are few diff erences, in both body size and years of life, between a “young” and an “old” adult male. Furthermore, considering that adult males of this species have an annual probability of survival of around 0.45 (Galán, 1999a), the proportion of “old” males in the population is scarce. Th erefore, a cue, such as the green dorsal coloration, which would indicate size-age diff erences between adult males would not be of great importance. By contrast, in the most long-lived species (I. monticola), there would be important diff erences between the diff erent adult males of the population in years of age. Hence, in this species, it would make more sense to have some kind of signal that 194 P. Galán / Animal Biology 58 (2008) 173–198 would make it possible for females to be able to clearly diff erentiate between young and old males. Female (former I. monticola cyreni) showed a strong preference for the scents of older and larger males (López et al., 2003). In other lizard species, females also select older males (Martín and Forsman, 1999; Irschick and Lailvaux, 2006). In I. monticola , the conspicuous green dorsal coloration increases throughout the lifetime of the lizards at the expense of the brown coloration, which decreases, i.e. the initially brown-pigmented scales turn green over the years. In this way, there is a transi- tion between a principally brown coloration, very similar to that of immature and female individuals, which the younger adult males have, towards a mainly green color- ation found in larger-sized and older males. Th e change in the dorsal coloration of the males after they reach sexual maturity has been described for other species of lacertids, both insular, Gallotia galloti (Th orpe and Brown, 1989) and Podarcis lilfordi (Bauwens and Castilla, 1998). In these two species, which are also longevous (Gallotia galloti reaches 8-9 years of age, Castanet and Báez, 1988), an increase in the dark dorsal pig- mentation of the males occurs as they grow, continuing after the minimum adult size has been acquired. Bauwens and Castilla (1998) suggest that these changes could be due to the accumulative action of sexual hormones, with individual diff erences being the result of the genetic diff erences between individuals. Since Darwin (1871) it has generally been acknowledged that the secondary sex- ual characteristics of males may have evolved for selection by females (sexual selec- tion). Many subsequent studies have confi rmed this, revealing that the selection by females is a powerful evolutionary force which has modifi ed the behaviour and mor- phology of many species (Andersson, 1994). However, as Olsson and Madsen (1995) have pointed out, selection by females has scarcely been described in lizards, a taxon which has been the subject of a considerable number of studies (Cooper and Vitt, 1993, for example, showed that the females of the non-territorial scincid, Eumeces laticeps , prefer to mate with the larger males). Furthermore, in territorial lizard spe- cies, such as the majority of iguanids (Stamps, 1983), and many lacertids (Bauwens, 1999), it is very diffi cult to show unequivocally if selection by the female is governed by characteristics of the male or by the quality of the territory (Hews, 1990). In this respect, it must be remembered that I. monticola is a territorial species (Moreira et al., 1999). In some lizard species, the conspicuous color of the males has evolved for aggressive intrasexual competition and not for mate selection by the female. In these species, in agonistic encounters between males, the success of an individual increases in proportion to the amount of green pigmentation cover (Olsson, 1994; Olsson and Madsen, 1995). In territorial lizard species an increase in conspicuous green coloration in the older males may imply a change in strategy, i.e. to visible stand out from other competitive males. Th e younger individuals, on the contrary, would tend to maintain less conspicu- ous (brown) colorations to call less attention to themselves. Th ese changes in colora- tion and strategy in the use of space with age have been described in Iberolacerta cyreni in Guadarrama (Aragón et al., 2004) and in other species of lacertids, such as in Psammodromus algirus (Díaz, 1993; Martín and López, 1999; Carretero, 2002). P. Galán / Animal Biology 58 (2008) 173–198 195

In these species, the change in coloration is linked to diff erent mating strategies: the older individuals carry out mate guarding of the female after copulation, while the younger ones would have to move away after copulating with the female, as they are in the territory of another male (sneakers versus territorial strategy). Th is change in strat- egy means that in the fi eld, only the greenest males would be carrying out mate guard- ing, although this is not necessarily related to mating success. Th is paper does not examine the relationship between coloration changes in adult males and their success in aggressive encounters or in obtaining and maintaining a ter- ritory. Th erefore, the close relationship between the green dorsal coloration cover and body size in I. monticola may, in turn, be related to the aggressive behaviour and fi ght- ing capacity against other males, as occurs in other lacertids (Olsson, 1994). In this case, fi eld observations of green males (not brown males) mating with females would not be related to a selection made by the females based on the color of the male but, more importantly, on the quality of the territory conquered by the male displacing other smaller (and brown) males. Given the high level of correlation between body size and age with the amount of green dorsal color, it could also be argued that, if the female does indeed make a selection, this would be based on size (or other attributes related to size) and not color. In order to see whether or not the female makes a selection based on color it would be necessary to include experiments where the dorsal color of the males would be changed with paint. With the results obtained, these fi ndings can only be consid- ered provisional. However, the importance of the changes in dorsal coloration observed in I. monticola adult males throughout their growth after maturity would indicate an interesting line of research on the social and sexual meaning of these colors, non-exclusive of the use of other communication signs, such as chemical signals, for example (López et al., 2003). In conclusion, on the basis of fi eld observations, I cannot state with certainty whether it is coloration or age (and size) that is the most important trait in determining the pairing success of I. monticola males. Nevertheless, the younger, smaller, brown-colored males could still enjoy reproductive success to that of the older, bigger and greener ones if the younger males carried out diff erent reproductive strategies (sneakers vs. mate guarding).

Acknowledgements Th e study was performed with authorisation from the regional government of Galicia (Servicio de Medio Ambiente Natural, Consellería de Medio Ambiente, Xunta de Galicia). Th e study was partially supported by the Secretaría Xeral de Investigación e Desenvolvemento of the government of Galicia, code number PGIDT99PXI10301A. Th is agency also granted the permits allowing us to collect the specimens in the fi eld and hold them temporarily in the laboratory (user establishment number 15006AE). We would like to thank Marta Rúa, and Ricardo Ferreiro for their assistance during the course of this study. I would like to thank Oscar Arribas and José Martín for their valu- able suggestions which have greatly improved the manuscript. 196 P. Galán / Animal Biology 58 (2008) 173–198

References Abell , A.J. ( 1998 ) Th e eff ect of exogenous testosterone on growth and secondary sexual character develop- ment in juveniles of Sceloporus virgatus . Herpetologica , 54 , 533 – 543 . Andersson , M. ( 1994 ) Sexual selection . Princeton University Press , Princeton, NJ . Aragón , P. , López , P. & Martín , J. ( 2004 ) Th e ontogeny of spatio–temporal tactics and social relationships of adult male iberian rock lizards, Lacerta monticola . Ethology , 110 , 1001 – 1019 . Arnold , E.N. ( 2004 ) Overview of morphological evolution and radiation in the Lacertidae . In: V. Pérez– Mellado , N. Riera , & A. Perera , (Eds.), Th e Biology of Lacertid Lizards. Evolutionary and Ecological Perspectives , pp. 11 – 36 . Institut Menorquí d’Estudis . Maó, Menorca . Arribas , O. ( 1996 ) Taxonomic revision of the iberian Archaeolacertae I: A new interpretation of the geo- graphical variation of Lacerta monticola Boulenger, 1905 and Lacerta cyreni Muller & Hellmich, 1937 (Squamata: Sauria: Lacertidae) . Herpetozoa , 9 , 31 – 56 . Arribas , O. ( 2002 ) Diseños en la banda ultravioleta en algunos lacértidos europeos: datos preliminares . Bol. Asoc. Herpetol. Esp. , 13 , 35 – 38 . Bauwens , D. ( 1999 ) Life-history variations in lacertid lizards . Nat. Croat. , 8 , 239 – 252 . Bauwens , D. & Castilla , A.M. ( 1998 ) Ontogenetic, sexual, and microgeographic variation in color pat- tern within a population of the lizard Podarcis lilfordi . J. Herpetol. , 32 , 581 – 586 . Bauwens , D. & Díaz-Uriarte , R. ( 1997 ) Covariation of life-history traits in lacertid lizards: a comparative study . Am. Nat. , 149 , 91 – 111 . Carranza , S. , Arnold , E.N. & Amat , F. ( 2004 ) DNA phylogeny of Lacerta (Iberolacerta) and other lacer- tine lizards (Reptilia: Lacertidae): did competition cause long-term mountain restriction? Systematics and Biodiversity , 2 , 57 – 77 . Carretero , M.A. ( 2002 ) Sources of colour pattern variation in mediterranean Psammodromus algirus . Neth. J. Zool. , 52 , 43 – 60 . Castanet , J. & Báez , M. ( 1988 ) Data on age and longevity in Gallotia galloti (Sauria, Lacertidae) assessed by skeletochronology . Herpetol. J. , 1 , 218 – 222 . Cooper , W.E. Jr & Greenberg , N. ( 1992 ) Reptilian coloration and behavior . In: C. Gans , & D. Crews , (Eds.), Biology of the Reptilia , vol. 18 , pp. 298 – 422 . Th e University of Chicago Press , Chicago . Cooper , W.E. Jr & Vitt , L.J. ( 1993 ) Female mate choice of large male broad-headed skinks . Anim. Behav . , 45 , 683 – 693 . Cuadrado , M. ( 2000 ) Body colors indicate the reproductive status of female common chamaleons: experi- mental evidence for the intersex communication function . Ethology , 106 , 79 – 91 . Darevsky , I. S. ( 1967 ) Rock lizards of the Caucasus . Indian National Scientifi c Documentation Centre, New Delhi . Darwin , C. ( 1871 ) Th e descent of man and selection in relation to sex . Murray , London . Díaz , J.A. ( 1993 ) Breeding coloration, mating opportunities, activity, and survival in the lacertid lizard Psammodromus algirus . Can. J. Zool. , 71 , 1104 – 1110 . Espmark , Y. , Amundsen , T. & Rosenqvist , G. ( 2000 ) Animal signals: signalling and signal design in animal communication . Tapir Academic , Trondheim, Norway . Fleishman , L.J. , Loew , E.R. & Leal , M. ( 1993 ) Ultraviolet vision in lizards . Nature , 365 , 397 . Galán , P. ( 1982 ) Nota sobre las Lacerta monticola Boulenger, 1905, de las zonas costeras del Norte de Galicia . Doñana, Acta Vertebrata , 9 , 380 – 384 . Galán , P. ( 1986 ) Morfología y distribución del género Podarcis Wagler, 1830 (Sauria, Lacertidae) en el noroeste de la Península Ibérica . Rev. Esp. Herp. , 1 , 85 – 142 . Galán , P. ( 1991 ) Notas sobre la reproducción de Lacerta monticola (Sauria, Lacertidae) en las zonas coste- ras de Galicia (Noroeste de España) . Rev. Esp. Herp. , 5 , 109 – 123 . Galán , P. (1995 ) Cambios estacionales de coloración y comportamiento agonístico, de cortejo y de apar- eamiento en el lacértido Podarcis bocagei . Rev. Esp. Herp. , 9 , 57 – 75 . Galán , P. ( 1996 ) Reproductive and fat body cycles of the lacertid lizard Podarcis bocagei . Herpetol. J. , 6 , 20 – 25 . Galán , P. ( 1997 ) Reproductive ecology of the lacertid lizard Podarcis bocagei . Ecography , 20 , 197 – 209 . P. Galán / Animal Biology 58 (2008) 173–198 197

Galán , P. ( 1999a ) Demography and population dynamics of the lacertid lizard Podarcis bocagei in Northwest Spain . J. Zool. (Lond.) , 249 , 203 – 218 . Galán , P. ( 1999b ) Declive y extinciones puntuales en poblaciones de baja altitud de Lacerta monticola can- tabrica . Bol. Asoc. Herpetol. Esp. , 10 , 47 – 51 . Galán , P. (2000 ) Females that imitate males. Dorsal coloration varies with reproductive stage in female Podarcis bocagei (Lacertidae) . Copeia , 2000 , 819 – 825 . Galán , P. & Fernández , G. ( 1993 ) Anfi bios e réptiles de Galicia . Edicións Xerais , Vigo . Germano , D. J. & Williams , D. F. ( 2007 ) Ontogenetic and seasonal changes in coloration of the blunt- nosed leopard lizard (Gambelia sila ) . Southwest. Nat. , 52 , 46 – 53 . Hawlena , D., Boochnik , R. , Abramsky , Z. & Bouskila, A. ( 2006 ) Blue tail and striped body: why do liz- ards change their infant costume when growing up? Behav. Ecol. , 17, 889 – 896 . Hews , D.K. ( 1990 ) Examining hypotheses generated by fi eld measures of sexual selection on male lizards, Uta palmeri . Evolution , 44 , 1956 – 1966 . Houde , A. E. ( 1997 ) Sex, color, and mate-choice in guppies . Princeton Univ. Press , Princeton, NJ . Irschick , D. J. & Lailvaux , S. P. ( 2006 ) Age-specifi c forced polymorphism: Implications of ontogenetic changes in morphology for male mating tactics . Physiol. Biochem. Zool. , 79, 73 – 82 . Küppers , H. ( 1994 ) Atlas de los colores . Blume ed., Barcelona . LeBas , N.R. & Marshall , N.J. ( 2000 ) Th e role of colour signalling and male choice in the agamid lizard Ctenophorus ornatus . Proc. R. Soc. Lond. B. , 267 , 445 – 452 . LeBas , N.R. & Marshall , N.J. ( 2001 ) No evidence of female choice for a condition-dependent trait in the agamid lizard Ctenophorus ornatus . Behaviour , 138 , 965 – 980 . Lemos-Espinal , J.A. , Smith , G.R. & Ballinger , R.E. ( 1996 ) Ventral blue coloration and sexual maturation in male Sceloporus gadoviae lizards . J. Herpetol. , 30 , 546 – 548 . López , P. , Aragón , P. & Martín , J. ( 2003 ) Responses of female lizards, Lacerta monticola , to males’ chemi- cal cues refl ect their mating preference for older males . Behav. Ecol. Sociobiol . , 55 , 73 – 79 . López , P. & Martín , J. ( 2001 ) Pheromonal recognition of females takes precedence over the chromatic cue in male Iberian wall lizards Podarcis hispanica . Ethology , 107 , 901 – 912 . López , P. , Martín , J. & Cuadrado , M. ( 2004 ) Th e role of lateral blue spots in intrasexual relationships between male iberian rock-lizards, Lacerta monticola . Ethology , 110 , 543 – 561 . Macedonia , J. M., Husak , J. F. , Brandt , Y. M., Lappin , A. K. & Baird , T. A. ( 2004 ) Sexual dichromatism and color conspicuousness in three populations of collared lizard (Crotaphytus collaris ) from Oklahoma . J. Herpetol. , 38 , 340 – 354 . Martín , J. ( 2005 ) Lagartija serrana - Iberolacerta monticola . In: L.M. Carrascal , & A. Salvador , (Eds.), Enciclopedia Virtual de los Vertebrados Españoles . Museo Nacional de Ciencias Naturales , Madrid . http://www.vertebradosibericos.org/ Martín , J. & Forsman , A. ( 1999 ) Social costs and development of nuptial coloration in male Psammodromus algirus lizards: an experiment . Behav. Ecol. , 10 , 396 – 400 . Martín , J. & López , P. ( 1999 ) Nuptial coloration and mate guarding aff ect escape decisions of male lizards Psammodromus algirus . Ethology , 105 , 439 – 447 . Moreira , P.L. , Almeida , A.P. , Rosa , H.D. , Paulo , O.S. & Crespo , E.G. ( 1999 ) Bases para a conservaçao da Lagartixa-da-montanha, Lacerta monticola. Estudos de Biologia e Conservaçao da Natureza no 25. ICN , Lisboa . Moreira , P. L. & Birkhead , T. R. ( 2003 ): Copulatory plugs in the Iberian Rock Lizard do not prevent insemination by rival males . Funct. Ecol. , 17 , 796 – 802 . Olsson , M. ( 1994 ) Nuptial coloration in the sand lizard, Lacerta agilis : an intra-sexually selected cue to fi ghting ability . Anim. Behav. , 48 , 607 – 613 . Olsson , M. ( 2001 ) No female mate choice in Mallee dragon lizards, Ctenophorus fordi . Evol. Ecol ., 15 , 129 – 141 . Olsson , M. & Madsen , T. ( 1995 ) Female choice on male quantitative traits in lizards-Why is it so rare? Behav. Ecol. Sociobiol. , 36 , 179 – 184 . Olsson , M. & Madsen , T. ( 2001 ) Promiscuity in sand lizards (Lacerta agilis) and adder snakes (Vipera berus ): causes and consequences . J. Hered. , 92 , 190 – 197 . 198 P. Galán / Animal Biology 58 (2008) 173–198

Olsson , M. & Shine , R. ( 1998 ): Chemosensory mate recognition may facilitate prolonged mate guarding by male snow skink, Niveoscincus microlepidotus . Behav. Ecol. Sociobiol . , 43 , 359 – 363 . Pinto, A.C.S. , Wiederhecker , H.C. & Colli , G.R. ( 2005 ) Sexual dimorphism in the Neotropical lizard, Tropidurus torquatus (Squamata, Tropiduridae) . Amphibia-Reptilia , 26 , 127 – 137 . Pough , F.H. , Andrews , R.M. , Cadle , J.E. , Crump , M.L. , Savitzky , A.H. & Wells , K.D. ( 2004 ) Herpetology ( 3th ed. ). Prentice Hall, Inc , New Jersey . Rand , M.S. ( 1992 ) Hormonal control of polymorphic and sexually dimorphic coloration in the lizard Sceloporus undulatus erythrocheilus . Gen. Comp. Endocrinol. , 88 , 461 – 468 . Rúa , M. & Galán , P. ( 2003 ) Reproductive characteristics of a lowland population of an alpine lizard: Lacerta monticola (Squamata, Lacertidae) in north-west Spain. Anim. Biol. , 53 , 347 – 366 . Sinervo , B. , Bleay , C. & Adamopoulou , C. ( 2001 ) Social causes of correlational selection and the resolu- tion of a heritable throat color polymorphism in a lizard . Evolution , 55, 2040 – 2052 . Stamps , J.A. ( 1983 ) Sexual selection, sexual dimorphism, and territoriality . In: R.B. Huey , E.R. Pianka , & T.W. Schoener , (Eds.), Lizard ecology, studies of a model organism , pp. 169 – 204 . Harvard University Press , Cambridge, Massachusetts . Stuart-Fox , D.M. , Moussalli , A. , Johnston , G.R. & Owens , I.P.F. (2004 ) Evolution of color variation in dragon lizards: quantitative test of the role of crypsis and local adaptation. Evolution , 58 , 1549 – 1559 . Taylor , H. L. & Caraveo , Y. ( 2003 ) Comparison of life story characteristics among syntopic assem- blages of parthenogenetic species: two color pattern classes of Aspidoscelis tesselata , A. exsanguis , A. fl agellicauda, and three color pattern classes of A. sonorae (Squamata: Teiidae) . Southwest. Nat. , 48 , 685 – 692 . Th ompson , C.W. , Moore , I.T. & Moore , M.C. ( 1993 ) Social, environmental and genetic factors in the ontogeny of phenotypic diff erentiation in a lizard with alternative male reproductive strategies . Behav. Ecol. Sociobiol. , 33 , 137 – 146 . Th orpe , R. & Richard , M. ( 2001 ) Evidence that ultraviolet markings are associated with patterns of molecular gene fl ow . Proc. Nat. Acad. Sci. USA , 2001 , 3929 – 3934 . Th orpe , R. & Brown , R.P. ( 1989 ) Microgeographic variation in the colour pattern of the lizard Gallotia galloti within the island of Tenerife: distribution, pattern and hypothesis testing . Biol. J. Linn. Soc. , 38 , 303 – 322 . Todd , A.C. ( 2005 ) Th e social mating system of Hoplodactylus maculatus . N. Z. J. Zool. , 32 , 251 – 262 . Tokarz , R.R. ( 1998 ) Mating pattern in the lizard Anolis sagrei: Implications for the mate choice and sperm competition . Herpetologica , 54 , 388 – 394 . Vitt , L. J. & Cooper , W. E. Jr. ( 1985 ) Th e evolution of sexual dimorphism in the skink Eumeces laticeps : An example of sexual selection . Can. J. Zool. , 63 , 995 – 1002 .